"It's also an opportunity for us, maybe, to get our suits up there before the astronauts actually have to wear them on the surface of the Moon ... this is all going to help take down risk for a subsequent landing."
Optical-based smoke alarms use light instead. They are slightly better at detecting the large smoke particles created by slow, smouldering fires. When such particles enter a chamber in the device, they scatter light from a small light source, which is then picked up by a photoelectric sensor.，更多细节参见heLLoword翻译官方下载
“脱贫的兜底必须是固若金汤的”，详情可参考WPS官方版本下载
Not the day you're after? Here's the solution to yesterday's Connections.，推荐阅读雷电模拟器官方版本下载获取更多信息
Фото: Jamal Awad / Reuters